/**
 * Copyright (c) 2003-2006, David A. Czarnecki
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list of conditions and the
 *     following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 *     following disclaimer in the documentation and/or other materials provided with the distribution.
 * Neither the name of "David A. Czarnecki" and "blojsom" nor the names of its contributors may be used to
 *     endorse or promote products derived from this software without specific prior written permission.
 * Products derived from this software may not be called "blojsom", nor may "blojsom" appear in their name,
 *     without prior written permission of David A. Czarnecki.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.blojsom.servlet;

import javax.servlet.ServletConfig;

import org.springframework.beans.factory.config.AbstractFactoryBean;

/**
 * Factory bean to return an instance of a {@link ServletConfig} object
 *
 * @author David Czarnecki
 * @since blojsom 3.0
 * @version $Id: ServletConfigFactoryBean.java,v 1.1 2006/03/20 21:31:17 czarneckid Exp $
 */
public class ServletConfigFactoryBean extends AbstractFactoryBean {

    private static ServletConfig servletConfig;

    /**
     * Return an instance of the {@link ServletConfig} object
     *
     * @return {@link ServletConfig}
     * @throws Exception If the servlet config has not been set on this factory bean
     */
    protected final Object createInstance() throws Exception {
        verifyState();

        return servletConfig;
    }

    /**
     * Returns <code>ServletConfig.class</code>
     *
     * @return <code>ServletConfig.class</code>
     */
    public final Class getObjectType() {
        return ServletConfig.class;
    }

    /**
     * Static method to set the servlet config instance
     *
     * @param servletConfig {@link ServletConfig} instance
     */
    public static void setServletConfig(ServletConfig servletConfig) {
        ServletConfigFactoryBean.servletConfig = servletConfig;
    }

    /**
     * Verify that the {@link ServletConfig} instance has been set on this bean
     *
     * @throws IllegalStateException If the {@link ServletConfig} instance has not been set
     */
    protected final void verifyState() throws IllegalStateException {
        if (servletConfig == null) {
            throw new IllegalStateException("You invoke the ServletConfigFactoryBean.setServletConfig() " +
                    "method prior to attempting to get the ServletConfig.");
        }
    }
}

